a. Field
The present disclosure relates to multistage matching networks.
b. Background
Applications such as large conversion ratio power converters and wireless power transfer often require circuit stages that provide voltage or current gains. Transformers can work as broadband gain stages with the added benefit of isolation. However, designing high-efficiency transformers at high frequencies, as required in radio-frequency converters and wireless power transfer applications, is challenging. In applications where isolation is not required and the switching frequency is relatively narrowband, matching networks are typically a more efficient alternative. For a given required gain, using multistage matching networks may be a more efficient solution than a single-stage network. Expressions have been derived for the optimum number of stages and the maximum efficiency achievable in such a multistage matching network. These design approaches have been of significant practical interest; however, these approaches constrain the input and load impedances of each stage of a multistage matching network to be purely resistive.